U.S. patent application number 17/212973 was filed with the patent office on 2021-10-07 for half-bridge module for an inverter of an electric drive of an electric vehicle or a hybrid vehicle and an inverter for an electric drive of an electric vehicle or a hybrid vehicle.
This patent application is currently assigned to ZF Friedrichshafen AG. The applicant listed for this patent is ZF Friedrichshafen AG. Invention is credited to Manuel Raimann, Ivonne Trenz.
Application Number | 20210313296 17/212973 |
Document ID | / |
Family ID | 1000005652157 |
Filed Date | 2021-10-07 |
United States Patent
Application |
20210313296 |
Kind Code |
A1 |
Raimann; Manuel ; et
al. |
October 7, 2021 |
HALF-BRIDGE MODULE FOR AN INVERTER OF AN ELECTRIC DRIVE OF AN
ELECTRIC VEHICLE OR A HYBRID VEHICLE AND AN INVERTER FOR AN
ELECTRIC DRIVE OF AN ELECTRIC VEHICLE OR A HYBRID VEHICLE
Abstract
The invention relates to a half-bridge module for an inverter in
an electric drive for an electric vehicle or a hybrid vehicle,
comprising a substrate, semiconductor switches arranged on the
substrate, power connections, and signal connections, wherein the
signal connections are electrically connected to the semiconductor
switches such that the semiconductor switches can be switched via
the signal connections, and wherein the power connections are
electrically connected to the semiconductor switches such that the
semiconductor switches allow or interrupt electricity transmission
between the power connections. The half-bridge module according to
the invention is distinguished in that the semiconductor switches
are in electrical contact in part via bond wires and in part via
lead frames. The invention also relates to a corresponding
inverter.
Inventors: |
Raimann; Manuel; (Salem,
DE) ; Trenz; Ivonne; (Friedrichshafen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ZF Friedrichshafen AG |
Friedrichshafen |
|
DE |
|
|
Assignee: |
ZF Friedrichshafen AG
Friedrichshafen
DE
|
Family ID: |
1000005652157 |
Appl. No.: |
17/212973 |
Filed: |
March 25, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 2924/10272
20130101; H01L 24/48 20130101; H01L 25/072 20130101; H02M 7/003
20130101; H01L 2224/40225 20130101; H01L 24/73 20130101; H01L
2924/13091 20130101; H01L 2924/1203 20130101; H01L 2924/13055
20130101; H01L 23/49838 20130101; H01L 2224/73221 20130101; H01L
24/37 20130101; H01L 2224/37012 20130101; H01L 2224/48225 20130101;
H01L 24/40 20130101; H01L 25/18 20130101 |
International
Class: |
H01L 23/00 20060101
H01L023/00; H01L 23/498 20060101 H01L023/498; H01L 25/18 20060101
H01L025/18; H01L 25/07 20060101 H01L025/07; H02M 7/00 20060101
H02M007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 3, 2020 |
DE |
102020204358.2 |
Claims
1. A half-bridge module for an inverter for an electric drive for
an electric vehicle or a hybrid vehicle, comprising: a substrate;
semiconductor switches arranged on the substrate; power connections
electrically connected to the semiconductor switches; and signal
connections electrically connected to the semiconductor switches,
wherein the semiconductor switches are configured to be switched
via the signal connections and allow or interrupt electricity
transmission between the power connections, wherein the signal
connections and the power connections are all arranged on a same
side of the substrate, and covered by a casting compound, and
wherein the power connections and the signal connections are
accessible from the same side of the substrate, such that the power
connections and the signal connections extend through the casting
compound, as seen from the same side of the substrate, and are
located within a base surface spanning the substrate, as seen from
the direction the power connections and the signal connections pass
through the casting compound, wherein the semiconductor switches
are in electrical contact in part via bond wires and in part via
lead frames.
2. The half-bridge module according to claim 1, wherein signal
contacts on the semiconductor switches are electrically contacted
via bond wires.
3. The half-bridge module according to claim 1, wherein the power
contacts on the semiconductor switches are electrically contacted
via the lead frames.
4. The half-bridge module according to claim 3, wherein, at least
in sections, the lead frames are wider than the semiconductor
switches.
5. The half-bridge module according to claim 3, wherein the
half-bridge module comprises a high-side circuit and a low-side
circuit, wherein the high-side circuit has exactly one dedicated
lead frame and wherein the low-side circuit has exactly one
dedicated lead frame.
6. The half-bridge module according to claim 3, wherein the lead
frames are designed such that their geometric forms contain a U
shape.
7. The half-bridge module according to claim 1, wherein the
semiconductor switches are designed as at least one of
insulated-gate bipolar transistors or silicon carbide
metal-oxide-semiconductor field-effect transistors.
8. The half-bridge module according to claim 7, wherein each
insulated-gate bipolar transistor has a dedicated freewheeling
diode (8).
9. The half-bridge module according to claim 1, wherein the
semiconductor switches are arranged in a planar configuration on an
upper surface of the substrate.
10. The half-bridge module according to claim 1, wherein each
semiconductor switch is arranged geometrically and electrically in
relation to a power connection identically to at least one other
semiconductor switch in relation to another power connection.
11. The half-bridge module according to claim 1, wherein the
half-bridge module comprises two additional electrical connections,
the electrical connection of which to the half-bridge module is
configured for returning to return a control current.
12. An inverter for an electric drive in an electric vehicle or a
hybrid vehicle, comprising at least three half-bridge modules
according to claim 1.
13. The half-bridge module according to claim 2, wherein the power
contacts on the semiconductor switches are electrically contacted
via the lead frames.
14. The half-bridge module according to claim 4, wherein the
half-bridge module comprises a high-side circuit and a low-side
circuit, wherein the high-side circuit has exactly one dedicated
lead frame and wherein the low-side circuit has exactly one
dedicated lead frame.
15. The half-bridge module according to claim 4, wherein the lead
frames are designed such that their geometric forms contain a U
shape.
16. The half-bridge module according to claim 5, wherein the lead
frames are designed such that their geometric forms contain a U
shape.
17. The half-bridge module according to claim 2, wherein the
semiconductor switches are designed as at least one of
insulated-gate bipolar transistors or silicon carbide
metal-oxide-semiconductor field-effect transistors.
18. The half-bridge module according to claim 2, wherein the
semiconductor switches are arranged in a planar configuration on an
upper surface of the substrate.
19. The half-bridge module according to claim 2, wherein each
semiconductor switch is arranged geometrically and electrically in
relation to a power connection identically to at least one other
semiconductor switch in relation to another power connection.
20. The half-bridge module according to claim 6, wherein each
semiconductor switch is arranged geometrically and electrically in
relation to a power connection identically to at least one other
semiconductor switch in relation to another power connection.
Description
[0001] This application claims priority from German Application No.
DE102020204358.2, filed on Apr. 3, 2020, the entirety of which is
hereby fully incorporated by reference herein.
[0002] The invention relates to a half-bridge module for an
inverter in an electric drive for an electric vehicle or a hybrid
vehicle as disclosed herein, and a corresponding inverter.
[0003] Both purely electric vehicles and hybrid vehicles are known
from the prior art, which are powered exclusively or partially by
one or more electric machines in the form of drive assemblies. To
supply the electric machines in these electric or hybrid vehicles
with electrical energy, the electric and hybrid vehicles comprise
electric energy storage units, in particular rechargeable electric
batteries. These batteries form DC voltage sources, although the
electric machines normally require AC voltage. For this reason,
there is normally a power electronics with a so-called inverter
interconnected between a battery and an electric machine in an
electric or hybrid vehicle.
[0004] These inverters normally comprise semiconductor switches,
usually formed by transistors. These semiconductor switches have
different degrees of integration, either as discrete individual
switches with a low degree of integration but high level of
scalability, bridge modules with a high degree of integration but
lower scalability, or as half-bridge modules, ranging between the
individual switches and the bridge modules with regard to the
degree of integration and scalability. Three half-bridge modules
typically form an inverter, such that the inverter has three
phases.
[0005] An electronic module is disclosed in DE 10 2006 050 291 A1,
which comprises a semiconductor power switch and a semiconductor
diode. A lower surface of the semiconductor power switch comprises
an output contact mounted on a chip field on a carrier strip, and
an upper surface of the semiconductor power switch comprises a
control contact and an input contact. An anode contact on the
semiconductor diode is located on the input contact on the
semiconductor power switch and electrically connected thereto. A
cathode contact on the diode is electrically connected to the
output contact on the semiconductor power switch.
[0006] DE 10 2006 008 632 A1 discloses a semiconductor power
component that comprises a flat lead frame, at least one vertical
semiconductor power component, and at least one more electronic
component. The vertical semiconductor power component has a first
side and a second side. At least one first contact surface and at
least one control contact surface are located on the first side,
and a second contact surface is located on the second side. The at
least one more electronic component is located on the second
contact surface on the vertical semiconductor power component.
[0007] A semiconductor module that has at least one first
semiconductor element is known from DE 10 2015 012 915 A1, which
has a first side with at least one first electrode, and a second
side with at least one second electrode, and has at least one
second semiconductor element that has a first side with at least
one first electrode and a second side with at least one second
electrode. The first semiconductor element is located above the
second semiconductor element, and an electrically conductive
connection is located between the first semiconductor element and
the second semiconductor element, wherein the at least one second
electrode on the first semiconductor element is mechanically and
electrically connected to the electrically conductive connection,
and the at least one first electrode on the second semiconductor
element is mechanically and electrically connected to the
electrically conductive connection.
[0008] A half-bridge module is known form the not yet published DE
10 2019 220 010.9 by the applicant, in which the signal connections
and the power connections are all located on the same side of the
substrate and encompassed in a casting compound. The power
connections and the signal connections can all be accessed from the
same side of the substrate such that the power connections and
signal connections extend through the casting compound, seen from
the same side of the substrate, and are located within a base
surface spanning the substrate, seen from the direction in which
they pass through the casting compound.
[0009] Depending on the actual arrangement of the semiconductor
switches on the underlying substrate, the known inverters have
numerous disadvantages, e.g. poor heat dissipation, uneven current
distribution, or they require a large installation space. An
improved heat dissipation normally requires a higher installation
space, and a smaller installation space normally results in poorer
heat dissipation. Likewise, a more even current distribution
results in poorer heat dissipation or likewise, a higher
installation space requirement, and vice versa. The inductive
properties of the inverter resulting from the selected arrangement
of the semiconductor elements must also be taken into account.
[0010] The object of the invention is to propose an improved
half-bridge module for an inverter in an electric drive for an
electric or hybrid vehicle.
[0011] This object is achieved according to the invention by the
half-bridge module for an inverter in an electric drive for an
electric or hybrid vehicle as disclosed herein. Advantageous
embodiments and developments of the invention can also be derived
from the instant disclosure.
[0012] The invention relates to a half-bridge module for an
inverter in an electric drive for an electric or hybrid vehicle
comprising a substrate, semiconductor switches, power connections
and signal connections located on the substrate, wherein the signal
connections are electrically connected to the semiconductor
switches such that the semiconductor switches can be switched via
the signal connections, and wherein the power connections are
electrically connected to the semiconductor switches such that the
semiconductor switches allow or interrupt an electrical power
transfer between the power connections. The half-bridge module
according to the invention is distinguished in that the
semiconductor switches are electrically contacted in part via bond
wires and in part via lead frames.
[0013] According to the invention, a half-bridge module is provided
that is designed for use in an inverter, wherein the inverter is
used for supplying an electric motor with AC current in an electric
or hybrid vehicle. The half-bridge module comprises a substrate,
which can be a DBC (Direct Bonded Copper) substrate, AMB (Active
Metal Brazing) substrate, or IM (Insulated Metal) substrate.
Semiconductor switches, as well as the associated power connections
and signal connections, in particular transistors and diodes, are
located on substrate. The substrate is preferably rectangular,
having two pairs of opposing side edges. The substrate can also be
square. The signal connections are used for switching the
semiconductor elements and are electrically connected to a signal
contact on the semiconductor switch. Depending on the design of the
semiconductor switch, the semiconductor switch can be switched
between on and off by providing current to the signal contact or
subjecting the switching surface to a voltage. The power
connections are electrically connected to power contacts on the
semiconductor switches, such that electricity can be transferred
from one power connection, through a semiconductor switch, to
another power connection. The electricity supplied to the electric
motor for powering the electric vehicle or hybrid vehicle is
provided via the power connections. In particular, there are
different types of power connections, specifically positive
connections, negative connections, and phase connections, wherein
the positive connections are used to supply electrical current, and
the negative connections are used to discharge electrical current.
The phase connections provide the actual AC voltage power supply
for the electric motor. The positive connections and the negative
connections are preferably located near side edges of the
substrate, i.e. the negative connections are located near the
shorter side edges of the substrate, and the positive connections
are located near the longer side edges. The half-bridge module
preferably comprises two positive connections and two negative
connections, although there can be more than just two positive
connections and negative connections, in order to be able to
conduct higher currents, for example. The phase connections are
preferably located opposite the negative connections, and likewise
near a shorter side edge of the substrate. The power connections
and the signal connections in the half-bridge module according to
the invention can all be accessed from the same side of the
substrate, preferably the upper surface. This means that the power
connections and the signal connections extend through the casting
compound from the same side of the substrate, and are located
within a base surface spanning the substrate seen from the
direction they pass through the casting compound. This makes it
possible to arrange the power connections in relation to one
another such that the half-bridge module has low leakage inductance
in the commutation cell in the order of a few nanohenrys, as well
as low leakage inductances in the signal connections. Both result
in switching with low losses. Another advantage of this design of
the power connections and signal connections is that they no longer
extend sideways, such that they are positioned outside the base
surface spanning the substrate. This results in advantages
regarding installation space.
[0014] According to the invention, the semiconductor switches are
electrically contacted in part via bond wires and in part via lead
frames, i.e. the signal contacts are electrically connected with
the signal surfaces and the power connections are electrically
connected to the power surfaces in part via bond wires and in part
via lead frames. This has the advantage of a very flexible
arrangement for the semiconductor switches on the substrate, and
therefore reducing or avoiding the aforementioned disadvantages in
the prior art, such that, in particular the relationship between
current distribution, installation space requirements, and heat
dissipation can be at least partially opened up, such that an
optimization of one of these properties leads only to a slight or
no degradation of the other two properties. Because lead frames
enable a comparatively even current distribution, and facilitate
conductance of higher currents, they are less flexible, and limit
the flexibility of the arrangement of the semiconductor switches
due to their structure. In contrast, bond wires are more flexible,
and therefore also enable a flexible arrangement of the
semiconductor switches on the substrate. With regard to the
possibility of ensuring an even current distribution, they are more
limited. As a result of the combination of electric contacts on the
semiconductor switches, in part with bond wires and in part with
lead frames, provided according to the invention, the advantages of
both contact possibilities can be combined on a half-bridge
module.
[0015] A bond wire can have an appropriate diameter and be made of
an appropriate material for the amperage that is to be conducted
therewith. The bond wire also does not have to have a round cross
section, e.g. copper with a diameter of 0.5 mm to 2.0 mm.
Rectangular or square cross sections can also be used.
[0016] The lead frames are stamped from sheet metal, and exhibit a
suitable thickness and material for the amperage that is to be
conducted. The lead frames preferably have a three dimensional
profile, i.e. there are rises generated by bending, preferably
located between two semiconductor switches or power connections
that are to be connected, and depressions caused by bending,
preferably for contact with semiconductor switches or power
connections. Each lead frame is a single element, and can connect
numerous semiconductor components and power connections to one
another. In particular because of the comparatively large surface
area and single element construction, as well as the resulting lack
of connecting points within a lead frame, a particularly even
current distribution is also obtained.
[0017] The semiconductor switches on the substrate of the
half-bridge module and the bond wires and lead frames are
advantageously coated with a casting compound. This protects the
semiconductor module from environmental effects, and in particular
from mechanical damages.
[0018] According to a preferred embodiment of the invention, the
signal contacts on the semiconductor switches are electrically
contacted via bond wires. Because the signal contacts are not
normally subjected to high amperages, or only require a voltage,
and an even distributability of the current therefore plays no, or
only an insignificant, role, a reliable switching of the
semiconductor switches can also be ensured by the electric contacts
obtained with a bond wire, wherein the bond wire is also flexible
enough that it can be arranged, e.g., around a lead frame, or above
a lead frame, thus never limiting the arrangements of the less
flexible lead frames. The possibilities for the spatial and
geometric arrangement of lead frames are therefore not limited.
[0019] According to another preferred embodiment of the invention,
the power contacts on the semiconductor switches are electrically
contacted via lead frames. This has the advantage that the
preference for lead frames, with regard to their even current
distribution and their good conductivity, in conjunction with the
high amperages to be supplied to or discharged from the power
contacts, can normally conduct higher amperages. If the signal
contacts are in electrical contact via bond wires, because of the
flexibility of the bond wire, there is nearly no need for concern
regarding the electrical contact to the signal contacts, such that
the lead frames can be designed exclusively according to the
requirements for an optimized current distribution, heat
dissipation, and installation space reduction. Lead frames also
enable a full surface contact with the power contacts, resulting
not only in low electrical resistances and an improved charge
carrier distribution in the semiconductor switches, but also in
heat dissipation from the semiconductor switches to the lead
frames, and from the lead frames into the environment.
[0020] According to a particularly preferred embodiment of the
invention, the lead frames are wider than the semiconductor
switches, at least in part. This results in a supplying and
discharging of electrical power to or from the semiconductor
switches with the lowest possible resistance. Because of the
enlarged surface area, the heat dissipation from the semiconductor
switches via the lead frames into the environment is improved.
[0021] According to another particularly preferred embodiment of
the invention, the half-bridge module comprises a high-side circuit
and a low-side circuit, wherein the high-side circuit has exactly
one dedicated lead frame, and the low-side circuit has exactly one
dedicated lead frame. The half-bridge module is therefore comprised
of two sub-circuits, specifically the high-side circuit and the
low-side circuit. The positive connections are assigned to the
high-side circuit, and the negative connections are assigned to the
low-side circuit. Both the low-side circuit and the high-side
circuit can be connected electrically to the phase connections. In
that both the high-side circuit and the low-side circuit each have
just one dedicated lead frame, the lead frames can have a
relatively large surface area, i.e. with a comparatively large
width and length. This further improves the conductivity and heat
dissipation.
[0022] According to another particularly preferred embodiment of
the invention, the lead frames are designed such that their
geometric form contains a U. This embodiment has proven to be
substantially optimal, because there is only a recess in the region
of the ends of the "U", or between the legs of the "U," which
allows bond wires to be attached to the signal connections.
Otherwise, the lead frames can exhibit a maximum length, width, or
surface area.
[0023] According to another particularly preferred embodiment of
the invention, the semiconductor switches form insulated-gate
bipolar transistors and/or silicon carbide
metal-oxide-semiconductor field-effect transistors. Insulated-gate
bipolar transistors are generally known as so-called IGBTs, and
silicon carbide metal-oxide-semiconductor field-effect transistors
are known in general as so-called SiC-MOSFETs. These types of
semiconductor switches are comparatively suitable for low-loss and
quick switching, and for high currents.
[0024] According to a particularly preferred embodiment of the
invention, each insulated-gate bipolar transistor has a dedicated
free-wheeling diode. The free-wheeling diodes protect their
dedicated insulated-gate bipolar transistors from inductive voltage
surges, in particular when switching electrical powers.
[0025] According to another preferred embodiment of the invention,
the semiconductor switches are arranged in a plane on an upper
surface of the substrate. This has the advantage of even better
heat dissipation.
[0026] According to another preferred embodiment of the invention,
each semiconductor switch is geometrically and electrically
arranged in relation to a power connection identically to at least
one other semiconductor switch in relation to another power
connection. This means that the half-bridge module has one or more
axes of symmetry, or a point of symmetry, at which arrangements of
semiconductor switches and power connections are mirrored. By way
of example, a first semiconductor switch can be electrically
connected to a positive connection via a lead frame or a segment of
a lead frame, and a second semiconductor switch can be electrically
connected to another positive connection via a geometrically
identical lead frame or geometrically identical segment of a lead
frame. As a result, both electrical connections have the same
resistance. A third and fourth semiconductor switch can also be
electrically connected to two negative connections via a
geometrically identical, potentially mirror reversed, lead frame,
or geometrically identical, potentially mirror reversed, segment of
a lead frame. This symmetry results in a very uniform current
distribution.
[0027] According to another preferred embodiment of the invention,
the half-bridge module comprises two additional electrical
connections, the electric connection of which to the half-bridge
module is configured as a return line for a control current. With
an insulated-gate bipolar transistor, one of the additional
electrical connections is used as a so-called Kelvin emitter, and
with a silicon carbide metal-oxide-semiconductor field-effect
transistor, one of the additional electrical connections is used as
a so-called Kelvin source. Both the Kelvin emitter and the Kelvin
source serve as return lines for a control current. The retroactive
effects of the load current to the control current are minimized by
this type of contact. Furthermore, a power connection in
conjunction with one of the two additional electrical contacts can
be used for inductive short circuit detection. The voltage drop
between the power connection and the additional electrical
connection is preferably measured for this.
[0028] The control current is sent to the signal contacts for the
semiconductor component, and switches the semiconductor component
either on or off.
[0029] The invention also relates to an inverter for an electric
drive in an electric vehicle or a hybrid vehicle, comprising at
least three half-bridge modules according to the invention. The
advantages described above in conjunction with the half-bridge
module according to the invention are therefore also obtained for
the inverter according to the invention.
[0030] The invention shall be explained below by way of example,
based on the embodiments shown in the figures.
[0031] Therein:
[0032] FIG. 1 shows, by way of example and schematically, a first
possible embodiment of a half-bridge module according to the
invention for an inverter in an electric drive for an electric
vehicle or a hybrid vehicle,
[0033] FIG. 2 shows, by way of example and schematically, a second
possible embodiment of a half-bridge module according to the
invention for an inverter in an electric drive for an electric
vehicle or a hybrid vehicle,
[0034] FIG. 3 shows, by way of example and schematically, a third
possible embodiment of a half-bridge module according to the
invention for an inverter in an electric drive for an electric
vehicle or a hybrid vehicle,
[0035] FIG. 4 shows, by way of example and schematically, a
possible embodiment of an inverter according to the invention for a
power electronics in an electric vehicle or a hybrid vehicle.
[0036] The same objects, functional units, and comparable
components have the same reference symbols throughout the figures.
These objects, functional units and comparable components are
identical with regard to their technical features, as long as not
otherwise specified, explicitly or implicitly, in the
description.
[0037] FIG. 1 shows, by way of example and schematically, a first
possible embodiment of a half-bridge module 1 according to the
invention for an inverter 20 in an electric drive for an electric
vehicle or hybrid vehicle. The half-bridge module 1 is composed of
a high-side circuit 1' and a low-side circuit 1''. It comprises a
substrate 2 in the form of a DBC (Direct Bonded Copper) substrate 2
with a ceramic carrier plate and copper coating on both sides, as
well as semiconductor switches 3, freewheeling diodes 8, power
connections 4, 5, 6, and signal connections 7, wherein the signal
connections 7 each have a signal connection contact pin 7'. The
copper coating is structured in numerous separate sections. The
half-bridge module 1 also comprises two additional electric
connections 9, the electrical connection to the half-bridge module
1 for which is designed to enable a so-called Kelvin sensing. This
minimizes the retroactive effects of the load current to the
control current. Furthermore, inductive short circuit detection is
enabled via a power connection in conjunction with one of the two
additional electrical connections. The voltage drop between the
power connection and the additional electrical connection is
preferably measured for this. Contact can be made to the two
additional electrical connections 9 via an additional electric
contact pin 9' provided for this. The power connections 4, 5, 6
form positive connections 6, negative connections 4, and phase
connections 5, and at least the positive connections 6 and the
phase connections 5 are electrically connected to the semiconductor
switches 3 via lead frames 11, such that the semiconductor switches
3 allow or interrupt electrical power transfer between the power
connections 4, 5, 6. The lead frames 11 can contain power contacts
3'' on the upper surface of the semiconductor switches 3 for this.
As can be seen in the illustration, the lead frames 11 exhibit a
greater width in at least one longitudinal middle section of the
half-bridge module 1 than the semiconductor switch 3. Both the
high-side circuit 1' and the low-side circuit 1'' are assigned to
exactly one lead frame 11, wherein each lead frame 11 is configured
such that its geometric form contains a U. This results in
comparatively low electrical resistances in the lead frames 11 and
an even current distribution in the half-bridge module 1. The
signal connections 7 are electrically connected to the
semiconductor switches 3 such that the semiconductor switches can
be switched via the signal connections 7. These signal connections
7 are electrically connected to signal contacts 3' in the
semiconductor components 3 via bond wires 10, and electrically
connected to the lead frames 11 via other bond wires 10, such that
an electrical switching current sent to the signal contacts 3' on
the semiconductor switches 3 can be returned via the power contacts
3'' and the lead frames 11. The semiconductor switches 3 are
designed as insulated-gate bipolar transistors according to this
example, also known as insulated-gate bipolar transistors (IGBT).
Each insulated-gate bipolar transistor 3 has a dedicated
freewheeling diode 8, for example, in order to protect the
insulated-gate bipolar transistors 3 from inductive voltage surges
when switching on electricity, which would otherwise destroy the
insulated-gate bipolar transistors 8.
[0038] FIG. 2 shows, by way of example and schematically, a second
possible embodiment of a half-bridge module 1 according to the
invention for an inverter 20 in an electric drive for an electric
vehicle or a hybrid vehicle. The half-bridge module 1 in FIG. 2
differs from the half-bridge module 1 in FIG. 1 by the design for
the semiconductor switches 3 as silicon carbide
metal-oxide-semiconductor field-effect transistors 3, also known as
siliciumcarbid metal oxide semiconductor field effect transistors
(SiC MOSFET), instead of as insulated-gate bipolar transistors 3.
As a result, there is no need for a freewheeling diode 8, but more
silicon carbide metal-oxide-semiconductor field-effect transistors
3 are needed than insulated-gate bipolar transistors 3 for
switching the same amperages. Accordingly, the half-bridge module
in FIG. 2 contains eight semiconductor switches 3, instead of just
four. The signal connections 7 and the geometric design of the lead
frames 11 are adapted to this larger number of semiconductor
switches 3, and just one lead frame 11 is used for the high-side
circuit 1' and just one lead frame 11 is used for the low-side
circuit 1''. Each lead frame 11 is also designed such that its
geometric form contains a U according to the exemplary embodiment
in FIG. 2.
[0039] FIG. 3 shows, by way of example and schematically, a third
possible embodiment of a half-bridge module 1 according to the
invention for an inverter in an electric drive for an electric
vehicle or a hybrid vehicle. The half-bridge module 1 in FIG. 3
differs from the half-bridge module 1 in FIG. 2 with regard to the
geometry of the lead frames 1. As can be seen in the figure, the
four silicon carbide metal-oxide-semiconductor field-effect
transistors 3 in both the high-side circuit 1' and the low-side
circuit 1'' are geometrically and electrically identically arranged
in relation to the power connections 4, 5, e.g. the negative
connections 4 and the phase connections 5. As a result of this
symmetry, the current distribution in the half-bridge module 1 is
extremely uniform. The lead frames 1 are geometrically adapted to
this arrangement of the semiconductor switches 3, and also exhibit
a U contained in their geometric forms in this exemplary
embodiment.
[0040] FIG. 4 shows, by way of example and schematically, a
possible embodiment of an inverter 20 according to the invention
for an electric drive in an electric vehicle or a hybrid vehicle.
The inverter 20 comprises six half-bridge modules 1 according to
this example, wherein each of the phase connections 5 are in
contact with two half-bridge modules 1 via a third, shared busbar
11a. The positive connections 6 and the negative connections 4 are
in contact with all six half-bridge modules 1 via a first shared
busbar 11b, or a second shared busbar 11c. The half-bridge modules
1 are arranged on a cooling device 12 in the form of a water cooler
via a sinter layer, not shown in FIG. 4.
REFERENCE SYMBOLS
[0041] 1 half-bridge module [0042] 1' high-side circuit [0043] 1''
low-side circuit [0044] 2 substrate [0045] 3 semiconductor switch,
silicon carbide metal-oxide-semiconductor field-effect transistor,
insulated-gate bipolar transistor [0046] 3' signal contact [0047]
3'' power contact [0048] 4 power connection, negative connection
[0049] 5 power connection, phase connection [0050] 6 power
connection, positive connection [0051] 7 signal connection [0052]
7' signal connection contact pin [0053] 8 freewheeling diode [0054]
9 additional electrical connection [0055] 9' additional electrical
contact pin [0056] 10 bond wire [0057] 11 busbar [0058] 11a third
busbar [0059] 11b first busbar [0060] 11c second busbar [0061] 12
cooling device, water cooler [0062] 20 inverter
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